Device for testing flash explosives



Feb. 21, 1961 Filed July 24, 1952 c. J. ZABLOCKI 2,972,247

DEVICE FOR TESTING FLASH EXPLOSIVES 2 Sheets-Sheet 1 CHARLES J. ZABLOCKI jmww BY ATTORNEYS Feb. 21, 1961 c, J z oc 2,972,247

DEVICE FOR TESTING FLASH EXPLOSIVES Filed July 24, 1952 2 Sheets-Sheet 2 FIG.2.

INVENTOR CHARLES d. ZABLOCKI 144. Had 1,,

ATTORNEYS United States Patent 6 DEVICE FOR TESTING FLASH EXPLOSIVES Charles J. Zablocki, Silver Spring, Md., assignor to the United States of America as represented by the Secretary of the Navy Filed July 24, 1952, Ser. No. 300,79

Claims. (Cl. 73-35) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a testing device and more particularly to an apparatus designed to test flash explosives by determining their firing characteristics when exposed to a burning hydrogen and oxygen gas mixture at varying pressures but at a preestablished ratio of two to one.

Formerly in providing a quality control means for flash detonators the ignition point thereof was determined by passing an .oxy-hydrogen torch past-the explosive. This method proved unsatisfactory in that the results obtained therefrom were completely unreliable. Thetemperature and flow rates of the gases could not be properly maintained and the torch tips were damaged from the detonation of the test charge Other apparatuses include that disclosed in the copending application of Frank W. Hayward, Charles J. Zablocki, and Kenneth R. Scribner, Serial No. 296,028, filed June 27, 1952, which matured into US. Patent No. 2,730,893, issuedrlanuary 17, 1956. This apparatus has limitations in that it is bulky, costly to mass produce, and, furthermore, the loading and unloading of detonators in that apparatus is not considered com pletely safe. The invention disclosed herein overcomes the objectionable features of the prior apparatuses referred to.

The present invention contemplates the provision of a safe, readily portable apparatus for testing flash fuse detonators and explosives in which the volume of the firing chamber may be varied by providing a plurality of interchangeable firing chambers. There is provided a base having an upright portion integral therewith on tion mounted on the lower surface of a master block.

Adapted to be attached to this sleeve portion is a firing chamber assembly which is a complete unit in itself and is adapted to contain the detonator to be tested; The explosive gas mixture is admitted to this chamber and a spark plug mounted in a wall of the chamber fires the mixture. It can be seen that firing chambers of various sizes and shapes may be used in conjunction with the presently disclosed apparatus in the event that tests employing varying degrees of shock and temperature are required. The apparatus is completely safe in that the lfiring chamber assembly can be removed from the stand in a completely closed condition andleft in that way until ICQ 2 chamberis a removable unit whereby firing chambers of varying size and shape may be utilized.

Another object of this inventionris to provide a device for testing flash detonators which is completely safe to operate and which may-be used continuously in quality control testing.

Another object of the present invention is to provide an oxygen hydrogen flash explosives tester which is comparatively inexpensive to produce andis readily portable.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a side elevation of the presently disclosed apparatus, and

Fig. 2 is the sectional view along the line 2-2 of Fig. 1.

There is provided a base 1 having an upright portion 2 integral therewithupon the upper end of which is dis posed the master block 3. The base has a circular bore 4 therein and is further provided with a firing switch. 5, a pilot light 6 and a spark plug lead holder 7. The master block 3 has a sleeve 8 secured Within the lower surface thereof which is provided with a flange-9 (Fig. 2) received in a rotatable locking ring 11. The locking ring is provided with internal interrupted threads 12 to receive the firing chamber assembly 13.

The master block.3 has a T-shaped gas port 14 therein extending from the upper surface thereof to the 10w end of sleeve 8. Screw threaded into the upper surface of the master block are yokes 15 and 16. The gas bottles 17 and 18, containing oxygen and hydrogen are fitted within yokes 15 and 16 respectively. The neck portion 19 of gas bottle 17 is held between clamping members 39 and 4-1 by means of screw 22 and the neck portion 21 of gas bottle 18 is retained between members 42 and43 by screw 23. Valves 24 and 25 disposed within theneck portions of the bottles are adapted to admit the gas to the T- shaped port in the master block.

The firing chamber assembly 13 is composed of upper and lower sections 26 and 27 which are adapted to, be

screwed together. The upper section of the firing chamber assembly forms a chamber 28 and'has a spark plug 29 mounted in the Wall thereof. The upper surface of the upper section is provided with guide pins 31 adapted to. be received in recesses 32 in the sleeve 8 The lower section 27 of the firing'chamber assembly comprises a loading platform 33 for the detonator on which is mounted a lead disc 34 adapted to receive the detonator 35.

silient mounting 44 for a bar 45 which extends'into engagement with the detonator holder and has a pallet 46 joined to or lapped on the outer end thereof. Sections 26 and 27 when secured together form the firing chamber for the detonator. The unit is moved to a position where in pins 31 are received in recesses 32 and the arms 36 on the locking ring 11 are rotated to cause the interrupted threads 12 on the locking ring to engage the threaded 'portion of section 26 thereby holding the firing chamber firmly in place in engagement with the sleeve 8. Valve 37, fitted within the upper section of the firing chamber, provides a means for closing off the firing chamber after the explosive gas mixture of oxygen and hydrogen has been admitted to the firing chamber.

The operation of the presently disclosed apparatus is as follows. A detonator is placed on the holder therefor within the lower section 27 of the firing chamber assembly and sections 26 and 27 are secured together. The unit is then moved upwardly and locked into place under sleeve 8 by rotatable locking ring 11. Valves Disposed in' an opening in the lower section is a vre- 24 and 25 are then opened to admit the desired oxygen hydrogen gas mixture to a pressure indicated by gage 38. The valves are then shut and valve 37 is also closed to seal off the firing chamber 28. Spark plug 29 is then energized by means of firing switch 5.

The energy output of the detonator may be determined in the following manner. The firing of the detonator will cause a compressionwave to travel the length of bar 45 through pellet 46. This wave returns as a tension wave and when this wave reaches the point of juncture of pellet 46 and bar 45 a separation occurs causing the pellet to be thrown on the bar. Photoelectric cells (not shown) spaced a fixed distance apart may be provided along the path of movement of the pellet. The length of time required for the pellet to pass through this fixed distance is a measure of the energy output of the detonator. The firing chamber assembly 13 is removed from engagement with the sleeve 8 after completion of the test and after the unit has cooled sufiiciently the sections may be disconnected to remove the fired detonator. In this manner an effective means is provided for quality control of flash detonators.

It is apparent that various sized firing chamber assemblies may be employed to suit any desired shock and temperature requirements and that, furthermore, it is possible to provide a plurality of apertures within the firing chamber for the reception of various instruments such as probes and pressure gages. The device is adaptable in that it is apparent that other gases may be employed for testing the detonators and that the firing chamber assembly may also be used for calorimetric work.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore .to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a device of the class described, a base, a member integral with said base and extending upwardly therefrom, a block mounted on said member, means supporting gas bottles mounted on the upper surface of said block, means for supporting a firing chamber disposed on the lower surface of said block, a removable hollow cylinder supported by said last-named means and forming a firing chamber adapted to contain a detonator to be tested, said hollow cylinder being formed in upper and lower sections, a T shaped port within said block in communication with said gas bottle supporting means and said hollow cylinder and having valve means associated therewith for supplying an explosive gas mixture to said firing chamber, and means mounted within the upper section of said hollow cylinder for firing said gas mixture; whereby the temperature sensitivity ofthe detonator which is disposed within the lower section of said cylinder may be determined.

2. Adetonator testing device comprising, a base, a member integral with said base and extending upwardly therefrom, a block secured to the upper end of said member, a plurality of gas bottle holding means mounted on the upper surface of said block, said block having formed therein port means providing communication be .tween said gas bottle holding means, a hollow cylinder com-prising a lower section and an upper section, detonator holding means mounted within the lower section of said cylinder and adapted to hold a detonator to be tested, the upper section of said cylinder forming a firing chamber, spark means mounted within a wall of said upper section, said cylinder having an aperture extending through a wall of the upper section thereof, means for securing said cylinder to said block with said aperture in alignment with the port means in said block for supplying an explosive gas mixture through said port means and aperture to said firing chamber; whereby upon energizing said spark means the temperature sensitivity of the detonator held withinsaid cylinder may be determined.

3. In a detonator testing device, a hollow member adapted to form a firing chamber into which an explosive mixture may be admitted,.means supported on said member and disposed within the firing chamber for igniting the explosive mixture, and means within said member for holding a detonator to be tested, said lastnamed means comprising a platform mounted within said member and a lead disc on said platform adapted to receive the detonator to be tested, and means including a bar in engagement with said platform for indicating the energy output of the detonator being tested upon firing thereof.

4. In a detonator testing device including a hollow member having means therewithin for supporting a detonator to be tested, and means comprising an elongated bar, said member having an opening in a wall thereof, resilient means mounting said bar in said opening with the major portion of the bar Within the member and an end of the bar disposed outside of the member, the other end of the bar engaging the means for supporting the detonator, and a pellet joined to the end of the bar disposed outside of the member; detonation of the detonator causing a compression wave to travel through the length of the bar and the pellet, the wave returning as a tension wave which upon reaching the juncture of the bar and.

pellet causes a separation therebetween with the result the pellet is thrown from the bar and thereby indicating the detonation of the detonator has occurred.

5. A detonator testing device comprising an upright support terminating in a laterally disposed block having a lower free end and a substantially horizontal circular flange thereon, a rotatable locking ring having a threaded portion and an annular surface engaging said flange for support thereby, a hollow member forming a firing chamber and having a threaded portion engageable by the threaded portion of said ring for detachably securing said member to said block in gas-tight relation, means within said chamber for holding a detonator or the like, said block having conduit means'including a conduit terminating at said lower free end thereof, said member having a conduit in communication with said chamber and said first-namedconduit, means separately containing gases which when mixed form an explosive mixture, said last-named means being connected to said conduit means for supplying an explosive mixture to said chainher, and means operatively connected to said member for igniting the explosive mixture in said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 

